How Many Catch Can Measurements Are Required to Evaluate the Hydraulic Performance of Drip Irrigation Systems?

Highlights The hydraulic performance of drip irrigation systems is important to evaluate because it is directly linked to water application efficiency, water consumption, and energy consumption. An accurate uniformity coefficient is achievable with only 64 catch cans for UC. These results encourage the growers to evaluate their drip irrigation system. Abstract. The hydraulic performance of drip irrigation systems is directly linked to water application efficiency, water consumption, and energy consumption. An accurate assessment of this hydraulic performance is needed to understand the system’s function and efficiency. However, direct measurement of drip irrigation system performance with catch cans is often labor-intensive and time-consuming. This study aims to find the minimum viable effort (fewest catch cans) required to evaluate drip irrigation system hydraulic performance by performing a series of extensive tests and down sampling systematically. Measurements from these tests are first compared with an established hydraulic model. Then they are used to determine the emitter flow rate, standard deviation, coefficient of manufacturer variation, emission uniformity, uniformity coefficient, and water distribution coefficient, respectively. The dripline length and distance from the pump are additional independent variables considered and were found to be not significant. Randomized down sampling of the catch can data shows that system performance is more likely to be overestimated if too few catch cans are deployed. Further, the uniformity coefficient converged to the correct classification with 64 cans, while the coefficient of variation converged to the correct classification with 256 cans. Keywords: Drip irrigation design, Emitter flow rate, Irrigation efficiency, Uniformity, Water distribution.